Stem cells are a class of multipotent cells capable of self-renewal. Under certain conditions, they can differentiate into various functional cells. Based on their developmental stage, stem cells are categorized into embryonic stem cells and adult stem cells. According to their developmental potential, they are divided into three types: totipotent stem cells (TSC), pluripotent stem cells, and unipotent stem cells (also known as specialized stem cells). Stem cells are undifferentiated and immature cells with the potential to regenerate various tissues, organs, and even the human body, earning them the name "universal cells" in the medical field.

On December 1, 2013, scientists at Columbia University Medical Center in the United States successfully converted human stem cells into functional lung cells and airway cells for the first time.

In April 2014, Ireland's first stem cell manufacturing center for human use was established at the National University of Ireland Galway, following approval by the Irish Medicines Board.

A very important member of the stem cell family is the mesenchymal stem cell (MSC), found in various tissues such as bone marrow, dental pulp, umbilical cord blood and tissue, placental tissue, and adipose tissue. MSCs are adult stem cells with multidirectional differentiation potential and are distinct from hematopoietic stem cells. They possess the ability to differentiate into various mesenchymal lineages (such as osteoblasts, chondrocytes, and adipocytes) as well as non-mesenchymal lineages, and have unique secretory functions for cytokines.

Due to their potential to regenerate various tissues and organs in the human body, research on stem cells and regenerative medicine has become one of the most captivating fields in the natural sciences. China leads the world in technologies such as low-temperature and ultra-low-temperature gas-phase and liquid-phase preservation of stem cells, directional temperature preservation, and anti-damage techniques for ultra-low-temperature stem cell storage. The continuous refinement of stem cell theory and the rapid advancement of related technologies are poised to bring about transformative outcomes in disease treatment and biomedical fields, representing a major revolution in traditional medical approaches and concepts.